Experimental Investigation On Resourceful Treatment Of Oily Sludge Through Extraction Method

Large amounts of oily sludge are produced during the oil and gas exploration, transportation and refining processes. Because of the high power consumption, high cost and resource wasting of the conventional treatment methods, the resouceful treatment of oily sludge was raised, which can recovery oil from oily sludge. In this work, traditional solvent extraction and microemulsion extraction methods were used in treating the oily sludge from two different places of Shengli oilfield. Oil phase was recovered from the oily sludge. Experimental results were analyzed to provide theoretical basis for industrial production.1# solvent and 2# solvent were used as the solvent to recovery oil from oily sludge SLT2(oily sludge A). The balance time of extraction, balance curve, the saturated concentration and the equilibrium distribution ratio were investigated. The possibility of solvent recovery were analyzed through experimental. It was found that the maximum ratio of extraction for oily sludge A is 78.61wt%.Microemulsions were made using acohol scan and salinity scan with surfactant, cosurfactant, salt, oil and water. The influence of surfactant, cosurfactant, salt, oil and water were investigated and discussed. It was found that with the increase of alcohol content and salt content, WinsorⅠ→WinsorⅢ→WinsorⅡcontinuous phase shift can happen in the microemulsion system. The structure change of W/O→bi-continuous structure→O/W, studied through conductance measurement, was established for the SDS/ n-butanol/ 2# solvent / water system and this provide theoretical support for the experiment.The microemulsions made with SDS as surfactants, n-butanol as co-surfactants, NaCl as salt, and 2# solvent as oil phase were used to treat the oily sludge B and the oily sludge C. The oily sludge B, which was artificially made, 34.88wt% oil content, and not seriously emulsified, was treated at room temperature with microemulsion. The oil extraction ratio reached 97.00wt%, under the condition of stirring time being 5 minutes, agent/mud ratio (ml/ g) being 4. While for the seriously emulsified the oily sludge C, the oil content being 18.21wt%, the oil removing rate was foud to be 79.22wt%.